Research Article Structural and Thermal Analysis of ...downloads.hindawi.com/journals/jen/2014/602087.pdf · Research Article Structural and Thermal Analysis of Asphalt Solar Collector

Research ArticleStructural and Thermal Analysis of Asphalt Solar CollectorUsing Finite Element Method

Jinshah Basheer Sheeba1 and Ajith Krishnan Rohini2

1Department of Automobile Engineering, KMCT College of Engineering, Kallanthode, Kozhikode, Kerala 673601, India2Department of Mechanical Engineering, Jyothi Engineering College, Cheruthuruthy, Thrissur, Kerala 679531, India

Correspondence should be addressed to Ajith Krishnan Rohini; [email protected]

Received 23 August 2014; Accepted 28 October 2014; Published 15 December 2014

Academic Editor: Guobing Zhou

Copyright © 2014 J. Basheer Sheeba and A. Krishnan Rohini. This is an open access article distributed under the CreativeCommons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided theoriginal work is properly cited.

The collection of solar energy using asphalt pavements has got a wide importance in the present energy scenario. Asphalt pavementssubjected to solar radiation can reach temperature up to 70∘C because of their excellent heat absorbing property. Many workingparameters, such as pipe diameter, pipe spacing, pipe depth, pipe arrangement, and flow rate, influence the performance of asphaltsolar collector. Existing literature on thermal energy extraction from asphalt pavements is based on the small scale laboratorysamples and numerical simulations. In order to design an efficient asphalt solar collector there should be a payoff between thethermal and structural stability of the pavement, so that maximum heat can be absorbed without structural damage due toexternal load condition. This paper presents a combined thermal and structural analysis of asphalt solar collector using finiteelement method. Analysis is carried out in different models so as to obtain optimum pipe spacing, pipe diameter, depth, and pipearrangement under the specified condition.

1. Introduction

Sustainable supply of energy is the key factor that determinesthe development of an economy. The current growth rateof energy consumption will lead to complete scarcity of themajor energy resource, fossil fuels, in the near future. Thesituation is most worrying because of the effect of majorpollutants like CO

2on the earth atmosphere. This situation

forced the researchers to think of green technologies bywhich the global energy production can be increased. Thispoints to the importance of distributed power generation.Distributed small scale production can increase the globalenergy production and at the same time it has an advantageof low transmission cost. Asphalt solar collector is not a newtechnology. This system is employed in many countries forthe purpose of heating and cooling of road pavements inwinter and summer, respectively. By proper design the tech-nology can be utilised to power some of the applications atthe site where it is utilized (distributed power generation).

Solar energy is the primary energy source for all otherforms of energy which is green thermal source distributed

around the globe. Road pavements can be considered as thelargest solar thermal collector cum storage system on land.It receives solar radiation all the day and stores some of theenergy from it. This energy is completely or partially dissi-pated to atmosphere by night time. Studies show that on anaverage summer day the temperature of an asphalt pavementcan reach up to 60–70∘ because of its excellent heat absorbingproperty. The solar thermal energy collected by the asphaltpavement can be harvested by circulating fluid through it. Asystem that is designed for this purpose is called asphalt solarcollector (ASC). Harvesting of thermal energy from asphaltpavement is a challenging technology for energy productionin the future.

An ASC consists of tubes or pipes embedded in thepavement through which a fluid, usually water, with anantifreezing agent is circulating. The collected energy can bestored as such or converted to any other form which suits theutility.There are three major benefits for the system: (a) if theheat can be collected with a reasonable efficiency and cost, itcan be considered as the energy source, (b) a part of the stored

Hindawi Publishing CorporationJournal of EnergyVolume 2014, Article ID 602087, 9 pageshttp://dx.doi.org/10.1155/2014/602087

2 Journal of Energy

heat can be utilised for heating the road in winter season toavoid ice formation, and (c) the extraction of heat in summerhelps to reduce the thermal stress development and therebyrutting. Many constraints arise on embedding the pipes inthe pavement. The major constraint is that it will affect thedurability and sustainability of the pavement. ACS can onlybe employed when building new road or at the time of largescale maintenance of the existing road. Not only the amountof energy extraction but also the variation of temperatureon the pavement surface is to be studied so as to avoid thedevelopment of thermal stress.

In order to design an efficient ASC there should be apayoff between the thermal and structural performance of thesystem.Optimumpipe depth, spacing, and flow rate for a par-ticular pipe diameter have to be designed to have maximumheat extraction without causing structural failure in adverseconditions. Many researches have been done to predict theperformance of the ASC numerically and experimentally.Some of the major works are described below. Zwarycz [1]designed a snow melting system operating between −16∘Cand 3∘Cand studied the performance.He observed anunevenheat transfer at the surface of the pavement. Loomans et al.[2] conducted numerical and experimental analysis to assessthe thermal potential of asphalt pavements. He found thatthe effectiveness of this system is less as compared to that ofconventional solar hot water heaters. Wu et al. [3] conducteda study in laboratory to find the effective heat exchanger thatcan extract maximum heat from the asphalt pavement. Theresults suggest that while using graphite content in themiddlelayer the temperature is reduced to a much lower valuecomparing to region that does not have graphite. Mallick etal. [4] presented the theoretical considerations obtained fromhis study that by selecting appropriate layer aggregates theharvesting of solar energy is feasible. Wu et al. [5, 6] hadnumerically and experimentally analysed the performance offull depth asphalt slab as a solar collector. Bobes-Jesus et al.[7] presented a literature review on the various parametersaffecting the performance of asphalt solar collector.

Pascual-Munoz et al. presented a new technology inwhich a multilayered pavement with a highly porous middlelayer is used instead of a solar collector with an embeddedpipe network. Excellent thermal efficiencies were obtained inthe laboratory tests. Efficiency values from 75% up to 95%were obtained depending on the irradiance from the solarlamp, porosity of the intermediate layer, and slope appliedto the collector. The authors also suggest that the addition ofmaterials such as graphite can be used to enhance the thermalproperties of the asphalt [8]. The influence of using differentkinds of materials in the asphalt solar collector is studiedby many researchers. Several experiments have been con-ducted to analyse the effect of raising the pavement thermalconductivity by the addition of aggregates of higher thermalconductivity such as graphite or quartz [4, 9]. This paperfocuses on the combined structural and thermal analysis ofasphalt solar collector having a fixed 20mm pipe diameter.Various models are examined in COMSOLMultiphysics 4.2bto predict the thermal performance; structural analysis isconducted in ANSYS APDL. The models are redesignediteratively to obtain an optimum design.

WindConvection

Pavement

Fill

Thermal

Conduction

Incidentsolar radiation

radiation

Figure 1: Various modes of heat transfer in asphalt pavement.

Computer simulation has become an essential part ofscience and engineering. Digital analysis of components isimportant when developing new products or optimizingdesigns because their real time experimentation is sometimesdifficult and costly. Today a broad spectrum of optionsfor simulation is available; researchers use everything frombasic programming languages to various high-level packagesimplementing advanced methods. A computer simulationenvironment is simply a translation of real-world physicallaws into their virtual form. COMSOL is all about to have asimulation environment that included the possibility to addany physical effect to your model. It is a flexible platform thatallows even preliminary users to model all relevant physicalaspects of their designs. COMSOL is equipped with a lotof packages for different studies. The package useful for ourstudy is the Heat Transfer Module, with customized physicsinterfaces for the analysis of heat transfer. Arbitrary couplingsto other applications modes in COMSOL Multiphysics arepossible within Heat Transfer Module; this is particularly rel-evant for systems based on fluid-flow as well as mass transfer.On the other hand ANSYS APDL is a well-proven module tosolve structural system that has complex parameters. It cangive a clear-cut idea about the structural performance of asystem with close tolerance to that of real time data. In thiswork we choose COMSOL for thermal analysis and ANSYSAPDL for structural analysis.

2. Energy Balance in Asphalt Pavement

The temperature distribution of an asphalt pavement isaffected directly by the thermal environment conditions towhich it is exposed. The primary modes of heat transferinclude incident solar radiation, thermal and long waveradiation between the asphalt pavement surface and the sky,convection due to heat transfer between the pavement surfaceand the fluid (air or water) that is in contact with the surface,conduction inside the pavement, and the radiation heat lossfrom surface. Figure 1 shows the various heat transfer modesin a heat conducting asphalt pavement exposed to solarradiation.

Journal of Energy 3

Table 1: Properties of material.

Layer Density, 𝜌(kg/m3)

Thermal conductivity, 𝑘(W/mK)

Specific heat, 𝐶𝑃

(J/kgK)Young’s modulus, 𝐸

(Mpa) Poisson ratio, 𝜇

HMA (layer 1) 2600 1.83 920 3500 0.4Base (layer 2) 2600 1.83 920 3500 0.45Subgrade (layer 3) 2200 1.7 1800 2800 0.45Copper tube 8700 400 385 1.1 × 105 0.34

Pipe depth

Detail APipe spacing

A

020mm, 2mm thickness

1000mm

1000mm

40mm

75mm

300mm

Figure 2: Straight pipe arrangement.

3. Thermal Analysis

From the literature it is clearly observed that the properties ofasphalt surfaces strongly depend on temperature. One of theimportant factors in deciding the life of the pavement is itsthermal response to solar radiation. A uniform temperaturealong the surface is a better option to avoid the thermalfailure. Our interest is to find out the optimum pipe spacingand pipe depth in asphalt pavement so as to make an almostuniform temperature distribution in asphalt pavement sur-face. In order to find out the temperature variation withinthe asphalt pavement and the amount of energy extractedby the circulating water we conduct simulation on variousmodels with different pipe spacing, pipe arrangement, andpipe depth and at different flow rates. Figures 2 and 3 showthe structure of the asphalt pavement we chose for ourstudy purpose. The pavement structure has a dimension of1000mm × 1000mm with a total depth of 415mm. Thestructure is inclusive of three layers as shown in Figure 4.

The thermal properties of each layer are given in Table 1.Two types of pipe arrangements are possible: straight pipeand serpentine. Straight pipe is commonly used due toits advantage in providing more uniform temperature atsurface. Serpentine arrangement can lead to nonuniformtemperature in asphalt layers; this is proven in our analysis.The blockage to pipe may lead to the overheating of surfacein case of serpentine arrangement, but in case of straight pipearrangement blocking of a single pipe will not affect thesystem.

In the asphalt structure, studies are conducted by varyingthe pipe spacing(s) and pipe depth 𝑑, keeping the pipediameter fixed at 20mm diameter and thickness of 2mm.The thermal analysis is conducted in COMSOLMultiphysics4.3b, Heat TransferModule. COMSOLMultiphysics is a finiteelement analysis, solver, and simulation software for variousphysics and engineering applications, especially coupledphenomena, or multiphysics.

4 Journal of Energy

Pipe spacing

020mm, 2mm thickness

1000mm

1000mm

Pipe depth

Detail AA

Figure 3: Serpentine arrangement of pipe.

Layer 1, 40mm thick

Layer 2, 75mm thick

Layer 3, 300mm thick

Figure 4: Model of pavement under study.

In the present study we choose Conjugate Heat Transfer-Laminar Flow Interface for our simulation. The ConjugateHeat Transfer-Laminar Flow Interface is used primarily tomodel slow-moving flow in environments where temperatureand energy transport are also an important part of the systemand must be coupled or connected to the fluid-flow in someway. The various modes of heat transfer between the asphaltlayers, pipe fluid, and the external environment are as follows:

(i) conduction through asphalt layers;

(ii) conduction through embedded pipes;

(iii) convective heat transfer from pavement surface toambient;

0

0.1

0.2

0.3

0.4

1

10.5

0.5

0

0

Domain 4Domain 3

Domain 2Domain 1

Top surface

zy

x

Figure 5: ASC model in COMSOL.

(iv) convective heat transfer from pipe wall to flowingwater;

(v) radiation heat transfer from asphalt surface.

Initially a 3D model consisting of the asphalt layer and fluiddomain is made using Autodesk Inventor 2013. The model isthen imported to theCOMSOL interface for thermal analysis.The asphalt solar collector model for study in COMSOL isshown in Figure 5 along with the domain details in Table 2.

Journal of Energy 5

Table 2: Domain details.

Domain 1 Top layer (HMA)Domain 2 Middle layer (base)Domain 3 Bottom layer (sublayer)Domain 4 Water domain

0

0.1

0.2

0.3

0.4

1 00.5

0.50

1

0.50.50

Figure 6: Meshed model.

Fluid domains are selected separately and the material wasassigned as water. The pipe material for the purpose of theasphalt solar collector is selected as copper due to its highthermal conductivity. The pipe wall is built into the model byHighly Conductive Layer Feature in Heat Transfer Module.A layer thickness of 2mm is provided in user interface withmaterial as copper. The details of various input conditionsfor analysis are provided in Table 3. Analysis is conducted ondifferent models with different pipe spacing and pipe depth.The details of models under analysis are given in Table 4.

The meshing of the entire domain was done by meshtool in COMSOL with a physics controlled mesh sequenceunder normal size element. The entire module is meshedwith free tetrahedral elements as shown in Figure 6. Thedetails of element size and number are given in Table 5. Ineach model, the pipe diameter (20mm) is made constant andthermal analysis was conducted and the surface temperaturedistribution was collected along the central line as shown inFigure 7 alongwith the outlet temperature of circulating fluid.The surface temperature can be directly obtained from theresult of the analysis by 3D group plot tool. Cutlines aredefined manually along the centre line to obtain the temper-ature along the cutline.

4. Structural Analysis

Strength of a system is determined by the weakest compo-nent. Embedding of tube system helps to reduce the thermalstress developed in the pavement. On the other hand theaddition of weak elements will affect the strength of thepavement. FEA is the powerful proven method to analysecomplex structures like asphalt pavements. Even though 3Dstructural analysis is superior to 2D plane strain analysis, thelarge longitudinal dimension makes it suitable for using 2Dplane stress analysis with close results. This part of analysishelps to determine the effect of tube layouts in the pavementstructure. Different models analysed in this paper are asfollows:

0

0.1

0.2

0.3

0.4

1

1

0.50.50

0Water outlet side

Water inlet side

Surface temperaturealong this line isanalysed for each

model

Figure 7: Surface temperature collection line and water inlet andoutlet region in straight pipe arrangement.

Figure 8: Finite element mesh for pipe spacing 150mm at a depthof 75mm.

(i) 200mm long pavement with 100mm tube spacing ata depth of 75mm;

(ii) 300mm long pavement with 150mm tube spacing ata depth of 75mm;

(iii) 300mm long pavement with 150mm tube spacing ata depth of 50mm;

(iv) 400mm long pavement with 200mm tube spacing ata depth of 75mm.

The depth of each layer is kept the same in all the models.The topmost HMA layer, middle base layer, and the bottomsublayer are considered to have a thickness of 40mm, 75mm,and 30mm, respectively. The finite element mesh boundarycondition, material properties, and load conditions are thesame for all the analysis. Quad 4 node 182 is chosen as theplane element type. Figure 8 shows the finite elementmesh ofthemodel.The bottom layer of the pavement is assumed to befixed to prevent both vertical and horizontal deflections. Theboundary nodes along the sides of the model are constrainedin the horizontal direction. Plane strain model used inthis analysis assumes the thickness in longitudinal directioninfinite. In all the analysis tyre pressure was taken as 0.7Mpa,weight was supported by tyre as 25 kN, and the water pressureis 0.72 pa (which is considered as negligible). Figure 9 showsthe load condition and constraints. Analysis is conducted on

6 Journal of Energy

Table 3: Input details for thermal analysis in COMSOL.

Thermal insulation Bottom surface insulatedPipe wall condition No slip boundary conditionInitial temperature 𝑇 initial = 300KHeat flux input 800W/m2, general inward heat flux condition on top surface of modelHighly conductive layer Boundaries of fluid domain selected layer thickness given as 2mm, material copperConvective heat flux User defined heat transfer coefficient given as 20W/m2K on top surface, 𝑇ambient = 300KSurface to ambient radiation User defined emissivity = 0.7, 𝑇external = 300KWater inlet temperature 𝑇 inlet = 298KInlet water velocity 8mm/sec–50mm/sec

Table 4: Models analysed.

Size of model Arrangement and short notation

1000mm × 1000mm, 𝑠 = 200mm, 𝑑 = 75mm Serpentine (pipe diameter 20mm), 200 × 75 serpStraight (pipe diameter 20mm), 200 × 75 str



1000mm × 1000mm, 𝑠 = 150mm, 𝑑 = 50mm Straight (pipe diameter 20mm), 150 × 50 str

Table 5: Mesh details.

Domain Domain 4 (water) OverallMinimum element size 0.0193m 0.1mMaximum element size 0.0644m 0.018m

FNFORRFOR

PRES

Figure 9: Load applied at the midsection.

each model at three different load conditions. In the firstanalysis external loads are applied at the surface in line withthe tube centre, in the second conditions the loads are appliedat the surface in midplane of the tubes, and in the third theloads are applied nearer to one tube.

5. Results and Discussion

The result obtained from our analysis is shown in Figure 13in a line graph. From the graph it is clearly understood thatthe surface temperature variation for serpentine fashion isvery high. For the cases of serpentine models, 200 × 75 serp,

150 × 75 serp, and 100 × 75 serp, the temperature variesfrom 318K to 328K. In case of 200 × 75 serp model thetemperature varies from 320K to 327K; there is an initialreduction in surface temperature in serpentine arrangementdue to large temperature difference during the initial timeof flow. Once the water is heated during its path along thepipe by extracting heat from asphalt layer through copperpipes, its temperature gradually increases and in later stages itcannot be able to absorbmore energy from asphalt layers.Thefinal result due to this is gradual increase in asphalt surfacetemperature from inlet to outlet along centre line. Hence theperformance of serpentine arrangement is poor in providinguniform surface temperature.We can see the effect of straightpipe arrangement on asphalt surface temperature variationfor different models, 200×75 str, 150×75 str, and 100×75 str.Clearly it is more uniform than serpentine arrangement, butthere is some regular asphalt surface temperature variationfrom pipe to pipe in the straight pipe arrangement. In caseof 200 × 75 str the surface temperature variation is within320K to 322K. On reducing the pipe spacing from 200mmto 150mm, keeping pipe depth the same, surface temperaturereduced due to more heat absorption from surface to flowingwater in pipe. But still there is a regular variation in surfacetemperature between pipes as in previous case of 200 ×75 str arrangement. To find the dependency of depth onthe surface temperature we conducted an analysis on 150 ×50 str arrangement where the depth is reduced to 50mm.The result obtained is not much satisfactory; even the surfacetemperature that reduced the temperature variation betweenpipes still exists. A 100×75 str arrangement canmake the tem-perature variation more uniform within 317.5 K. Temperaturevariation within asphalt layers for 100 × 75 str arrangementsolved by COMSOL is shown in Figure 10. The temperaturedistribution within the pipes where water is flowing is shown

Journal of Energy 7

10.50

10.5 0

y

x

Volume: temperature (K)

320

315

310

305

300

298

321.11

Figure 10: Temperature variation within asphalt layers for 100 ×75 str arrangement.

z

y

1

0.5

0

Volume: temperature (K)

0.2 0.4 0.6 0.820×10−3

304

303

302

301

300

299

298298

304.75

Figure 11: The temperature distribution within the pipes.

in Figure 11.Themaximum temperature obtained at outlet byanalysis is 304.7 K, that is, a 6.7∘C temperature rise.

Nowwhenwe consider the fact of outlet temperature vari-ation in case of different models, we can see amaximum tem-perature is attained by the serpentine arrangement as shownin Figure 12. The water outlet temperature is higher in threeserpentine arrangement cases when compared to straightpipe arrangement.Maximum temperature of 322K is attainedby 100 × 75 serp arrangement, which is a 24∘C rise comparedto inlet.

It is important to consider the structural aspect alsobecause reducing pipe spacing and reducing pipe depth willlead to damage of pipes and road surfaces due to loadsexerted from vehicles.The result from structural analysis alsoneeds to compare to fix the spacing and depth. On analysingdifferent models with different pipe spacing and depth,the results show all the models were under safe operation.Figures 14 and 15 show the von Mises stress distribution inthe 150 × 75 str model examined. From the plot it is clear

200×75

serp

200×75

str

150×75

serp

150×75

str

100×75

serp

100×75

str

150×50

str

Model

Out

let w

ater

tem

pera

ture 325

322319316313310307304301298

Water outlet temperature variation

Figure 12: Outlet water temperature for different pipe arrange-ments.

315317319321323325327

0 6 9 13 17 19 23 26 29 35 39 45 53 54 66 72 79 86 92 93 99 100

Surface temperature plot

100 × 75 serp100 × 75 str150 × 50

150 × 75 serpstr

150 × 75 str200 × 75 serp200 × 75 str

x-domain (widthwise)

Surfa

ce te

mpe

ratu

re

Figure 13: Surface temperature collection line and water inlet andoutlet region in straight pipe arrangement.

0.331E + 070.294E + 070.257E + 070.221E + 070.184E + 070.147E + 070.110E + 077351973675980.145E − 09

Figure 14: Stress distribution when load is applied at the middle.

0.401E + 070.357E + 070.312E + 070.268E + 070.223E + 070.178E + 070.134E + 078921214460600.109E − 09

Figure 15: Stress distribution when load is applied eccentrically.

8 Journal of Energy

Table 6: Result of stress analysis.

Model Load applied on surfacein line with the tube Load applied at midplane

Load appliedeccentrically betweenthe tubes at surface

100 × 75mm 0.23 × 107 pa 0.298 × 107 pa 0.314 × 107 pa150 × 75mm 0.287 × 107 pa 0.31 × 107 pa 0.41 × 107 pa150 × 50mm 0.41 × 107 pa 0.285 × 107 pa 0.41 × 107 pa200 × 75mm 0.291 × 107 pa 0.33 × 107 pa 0.490 × 107 pa

0.225E − 03

0.200E − 03

0.175E − 03

0.150E − 03

0.125E − 03

0.100E − 03

0.751E − 04

0.501E − 04

0.250E − 04

0.151E − 17

Figure 16: Strain distribution.

that the maximum stress is developed at the interface ofcopper tube and within the tube. Within the asphalt thestress is within permissible limit [10]. Since the temperatureis maximum at the surface of the pavement the stress valuedecreases with depth and becomes maximum at the interfacebetween the pavement and the copper tubes. This shows thatthe possible mode of failure may be because of fatigue andcreep. Within the copper the maximum stress developed is0.490 × 10

7 pa, which is for the model 200 × 75 str when theload is applied eccentrically between the tubes at the surface.This value is very small when compared to the safe stress for acopper tube [11]. Table 6 shows the result of von Mises stressin different models. Figure 16 shows the strain distribution inthemodel. From the result it is clear that themaximum strainis at the layer just below the application of load. The value isin the order of 0.0001 which is negligible. The deformationis in the order of micrometres. For further analysis the first,second, third, and fourth principle stresses have been plotted.From the analysis the maximum value is obtained for thethird principle stress as shown in Figure 17.

6. Conclusions

The numerical study conducted on ASC shows that boththe pipe depth and pipe spacing strongly influence thetemperature distribution within the pavement. Within acertain limit the structural stability is not affected much. Asthe structural and thermal properties of ASC are subjected tovary with prevailing temperature condition,mix proportions,and compactness of the pavements, the exact performancecan only be predicted by conducting real time experimentson large models. Numerical study is enough to predict the

0

−353834

−707667

−0.106E + 07

−0.142E + 07

−0.177E + 07

−0.212E + 07

−0.248E + 07

−0.283E + 07

−0.318E + 07

Figure 17: Third principle stress.

behaviour of such system under certain assumptions. Asan initial study numerical analysis is conducted on asphaltmodels with different pipe length and pipe spacing [100 ×75mm, 150 × 75mm, 150 × 50mm, and 200 × 75mm] andpipe arrangement by keeping both pipe diameter and flowrate constant. The result of analysis proves that reducing thepipe spacing will improve the quality of temperature profileat the surface of the pavement. At a spacing of 100mmand depth of 75mm nearly a uniform temperature profile isobtained on the pavement surface. Even more quality willbe obtained if we go on reducing the spacing but it willreduce the solidity of the pavements. This added-up weakcomponent will reduce the strength of the road pavement. Asthe pipe depth reducesmore energy can be extracted. In orderto maintain a structural safety a depth of 75mm is advisable.Serpentine arrangements are not advisable as the temper-ature at the pavement surface increases linearly inducinglarge thermal stress in the pavements.Hencewe conclude thatthe optimum spacing and depth as 100mm × 75mm straightarrangement.

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper.

Acknowledgment

The authors thank Jesseela S, Assistant Professor inMechanical Department, Government Engineering College,Kozhikode, for her support and valuable advice during thisresearch.

Journal of Energy 9

References

[1] K. Zwarycz, SnowMelting andHeating SystemBased onGeother-mal Heat Pumps at Goleniow Airport, Poland, Reports, TheUnited Nations University, 2012.

[2] M. G. L. C. Loomans, H. Oversloot, A. de Bondt, R. Jansen,and H. van Rij, “Design tool for the thermal energy potentialof asphalt pavements,” in Proceedings of the 8th InternationalIBPSA Conference, vol. 8, pp. 745–752, Eindhoven, The Nether-lands, August 2003.

[3] S. Wu, M. Chen, H. Wang, and Y. Zhang, “Laboratory studyon solar collector of thermal conductive asphalt,” InternationalJournal of Pavement Research and Technology, vol. 2, no. 4, pp.130–136, 2009.

[4] R. B.Mallick, B.-L. Chen, and S. Bhowmick, “Harvesting energyfrom asphalt pavements and reducing the heat island effect,”International Journal of Sustainable Engineering, vol. 2, no. 3, pp.214–228, 2009.

[5] S.Wu,H.Wang,M. Chen, andY. Zhang, “Numerical and exper-imental validation of full-depth asphalt slab using capturingsolar energy,” in Proceedings of the 4th International Conferenceon Bioinformatics and Biomedical Engineering (iCBBE ’10), pp.1–4, Chengdu, China, June 2010.

[6] W. Shaopeng, C. Mingyu, and Z. Jizhe, “Laboratory investi-gation into thermal response of asphalt pavements as solarcollector by application of small-scale slabs,” Applied ThermalEngineering, vol. 31, no. 10, pp. 1582–1587, 2011.

[7] V. Bobes-Jesus, P. Pascual-Munoz, D. Castro-Fresno, and J.Rodriguez-Hernandez, “Asphalt solar collectors: a literaturereview,” Applied Energy, vol. 102, pp. 962–970, 2013.

[8] P. Pascual-Munoz, D. Castro-Fresno, P. Serrano-Bravo, and A.Alonso-Estebanez, “Thermal and hydraulic analysis of multi-layered asphalt pavements as active solar collectors,” AppliedEnergy, vol. 111, pp. 324–334, 2013.

[9] H. Wang, S. Wu, M. Chen, and Y. Zhang, “Numerical sim-ulation on the thermal response of heat-conducting asphaltpavements,” Physica Scripta, vol. 3, 2010.

[10] AASHTO, Guide for Design of Pavement Structures, AmericanAssociates for State Highway and Transportation Officials,Washington, DC, USA, 1993.

[11] I.S.I.2825-1969, Code for Pressure Vessel Design, Bureau ofIndian Standards, New Delhi, India, 1969.

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Research Article Structural and Thermal Analysis of ...downloads.hindawi.com/journals/jen/2014/602087.pdf · Research Article Structural and Thermal Analysis of Asphalt Solar Collector